Home > Optoelectronic Circuits >Optoelectronic Display Circuits > Light controlled delay circuit (1)

Light controlled delay circuit (1)

Source: InternetPublisher:两手空空 Keywords: Light control delay circuit BSP electric lamp Updated: 2021/08/06

204.<strong>Light control</strong><strong>Delay circuit</strong> (1).gif

At night, turn off the lights to rest or go outside, and do not allow the darkness to explore around the bed or around the room. It would be much more convenient if another small lamp could automatically light up for dozens of seconds when the light is turned off . The light-controlled delay lamp   introduced in this example is controlled by indoor light. When there is light in the room, the small lamp will turn on; when the light in the room suddenly changes from bright to dark, the small lamp will light up and delay for tens of seconds. Finally, it can self-extinguish , and its circuit is shown in Figure 204.     G.C. , VDl-VD4 and vs, etc. form a simple power circuit, which outputs about 12V DC voltage to power the whole machine . RL is a photoresistor. When the indoor light is strong, it shows low voltage H【, c. The trapped charge passes through RI. , Vn5 is leaking, VT terminal cannot get the base bias current and is cut off, relay K does not operate, and small lamp E does not light up. When the indoor lights are turned off , the light becomes dim, RI. Immediately presents a high resistance, (1. It begins to charge through the ruler, R. and VT emitter junction, vr therefore obtains the base bias current and conducts. The relay K is attracted, its moving contact point kl is closed, and the lighting lamp E is turned on. It emits light when energized. After tens of seconds, the G charge base is fully charged, and the charging current gradually reduces to zero. The relay K loses power and is released, and the small lamp E goes out. If the light is turned on for the second time or at dawn in the morning, RL returns to low Level, (1. It can be discharged through RL, VI)5, and f returns to the original state.     C. Use Cl'iFl-400V polypropylene resistor, RI_ use MG45 type photoresistor, etc., island resistor is required The larger the difference between the phase difference and the hidden phase, the better. K can use IZC, -22F, DC12V small medium-power electromagnetic relays. The requirements for other components are as shown in the figure.
























EEWorld
subscription
account

EEWorld
service
account

Automotive
development
circle

About Us Customer Service Contact Information Datasheet Sitemap LatestNews


Room 1530, 15th Floor, Building B, No.18 Zhongguancun Street, Haidian District, Beijing, Postal Code: 100190 China Telephone: 008610 8235 0740

Copyright © 2005-2024 EEWORLD.com.cn, Inc. All rights reserved 京ICP证060456号 京ICP备10001474号-1 电信业务审批[2006]字第258号函 京公网安备 11010802033920号